I got a comment the other day that led me to believe that I still hadn’t done a decent enough job in explaining the parameters of what grading is or isn’t. I asked if I could quote her but I haven’t heard back from her. Still, she did post it to the blog so I guess I can quote her although I won’t mention her name. She wrote:
Specifically, I want to go from my size 14 to a line for sm, med, lg and in petite, regular, tall and obese sizes. I can use my creativity and make the designs and give them to a pro to redraw into the sizes I need for production. I do need to figure out the measurements so patterns can be graded.
In a nutshell, some differences are too great to be graded in. You can only grade sizes within a given sizing category. For example, children’s wear people seem to face this issue the most. Very often, they want one style to be graded from a 6mo infant all the way up to size 14 girls. This simply cannot be done (see pp. 170-171 of the Entrepreneur’s Guide). Not well anyway. The bodies are too different. You can’t grade in all of these differences and expect the design to execute well. Specifically regarding the comment above, you can’t grade a regular (or a tall or bbw or whatever) into small, medium, and large etc and then turn around and take the same pattern and regrade that regular into a tall with commensurate smalls, mediums, larges that apply to it. It just doesn’t work that way. Grading can only make an existing shape larger or smaller. You cannot change shapes with grading. Going from a petite to a bbw is changing shapes. Below are two sketches from pg. 170 (in pdf ) of The Entrepreneur’s Guide, perhaps these will explain it visually. Grading only makes an existing shape larger or smaller but it does not change the shape.
If one has their heart set on selling S-M-L-XL in petites, regulars, talls and bbw, this means four different body shapes (petites, regulars etc) with four sizes per category. One would need to develop each pattern for each body shape and then have each one graded. Grade rules are complex as it is and this is just way too much. Developing grade rules for sizes within whatever size category can take hours and adding the parameters of additional distances needed for other body shapes is beyond unwieldy. And that’s beside the point that some details just don’t translate well in both the smaller and larger sizes. It remains an issue of proportion. Rather, one must develop a pattern for each differently shaped body and then grade that given shape.
For another view of grading in applied detail, I’m sending you to Esther. Esther is a pattern maker (and retailer) who specializes in children’s wear. Luckily for you, she also blogs. Even better, she’s blogged about grading children’s wear. She has even blogged about the implications of sku management and sizing; what more could you ask for? Rather than summarize her fine work, I’ll leave you the links for further reading. Thanks for the links Esther!